In recent years, display devices with a greater display area on the surface are highly anticipated because of higher performance and advanced design in the technical field of mobile data communication devices such as mobile phone and personal digital assistant (PDA). For example, display devices including a thinner bezel structure are proposed. which a driver is mounted in the periphery of the display area on the substrate including electrodes. In display devices using such a structure of the driver, input signals and voltages are supplied to the driver through a wiring substrate such as a flexible printed circuit (FPC). However, in consideration of greater production and thinner bezel structure, there has been a study to omit such a flexible printed circuit but to achieve an electrical connection between lines formed on the lower surface side of an array substrate and the driver formed on the upper surface side of the array substrate through a contact hole passing through the array substrate.